Connecting system for surface coverings

ABSTRACT

A spline, tongue, connector, or snap connector is described and useful for connecting a variety of surface covering products together. In one embodiment the spline is a polymeric material having an elongated shape and dimensions such that the spline has a sufficient width to fit into and extend outside of a groove in a side edge of a first plank and to fit into a respective groove in a side edge of a second plank. The spline may be concealed from view when the first plank and the second plank are connected together by the spline. A surface covering system for connecting two or more planks together is also described as well as methods to connect two or more planks together using the splines of the present invention.

This application is a continuation-in-part of prior U.S. patentapplication Ser. No. 09/630,121 filed Aug. 1, 2000, which is acontinuation-in-part of U.S. patent application Ser. No. 09/460,928filed Dec. 14, 1999, both of which are incorporated in their entiretiesby reference herein.

BACKGROUND OF THE INVENTION

Commercially available laminate flooring (using high or medium densityfiberboard or particle board as the core layer) has gained overwhelmingsuccess in the flooring market. The growth rate of the laminate flooringhas remained in the double digits since the product was introduced inthe United States market. The success of this product is credited tocertain properties such as stain resistance, wear resistance, fireresistance, good cleanability, and the ability to use just about anytype of printed design. In addition, the overall emission of organiccompound vapor is low and the laminate flooring is considered colorstable and environmentally friendly over other competing flooringproducts.

The biggest concern with commercially available laminate flooring is themoisture resistance of the finished product and the sensitivity of theraw materials (high or medium density fiberboard, paper, and particleboard) to moisture during the manufacturing process. In some instances,the moisture can lead to some serious quality control issues andapplication restraints. For instance, and just to name a few, the highermoisture content in the product, such as in the particle board orfiberboard, can cause blistering and adhesion failure of the melaminesurface to the core. Also, higher moisture contents can lead todimensional instability of the finished product, which then results inthe cupping or doming of the product, which is extremely undesirable,especially when installers are laying down the flooring. Also, excessivemoisture contents can create edge peaking due to the swelling of theproduct and such edge peaking can result in edge chip-off or prematurewear-out or can soil more quickly. The susceptibility to moisturecontent also leads to some installers not wishing to place such laminateflooring in areas which are subject to having water on the surface ofthe floor, such as in the kitchen and bathroom areas.

The suppliers of such laminate flooring have appreciated the problemsassociated with their products and have attempted to overcome theseproblems by developing laminate flooring having better moistureresistance by using melamine, phenolic, or isocyanate binders topartially replace urea resins present in the laminate flooring. Whilethis improvement has made the product more moisture resistant, thecurrent commercially available laminate floorings are still prone tomoisture damage. For instance, the thickness swelling of laminateflooring can increase by 10% and water absorbency can exceed more than15% according to the 24 hours water absorption test. Another attemptedsolution at reducing the moisture resistance weaknesses of currentlaminate flooring has led some manufactures to apply a water-repellantmaterial on the upper edges of the tongue and groove areas which furtherserve to resist any moisture penetration through joints. Still anotherattempted solution involves applying silicone caulk to seal the edgesand voids of the laminate perimeter where the laminate flooring meetsthe wall. However, if very stringent installation instructions are notfollowed, the laminate flooring will still be subjected to moisturedamage.

Accordingly, there is a need to develop flooring systems which overcomethe above weaknesses and disadvantages of current commercially availablelaminate flooring.

SUMMARY OF THE INVENTION

A feature of the present invention is to provide a spline, tongue,connector, snap connector, or other joining system element, hereinreferred to as a spline, which can be used in a surface covering systemand which preferably provides improved moisture resistance and is notsusceptible to damage caused by moisture.

Another feature of the present invention is to provide a spline forlaminate planks and other surface coverings which is economicallyfeasible and permits easy installation and flexibility.

Still another feature of the present invention is to provide a surfacecovering system which has significant improvements with respect to easeof installation and includes a foolproof installation design andtechnique.

Another feature of the present invention is to provide a surfacecovering system which avoids the use of a wet adhesive applicationmethod.

Another feature of the present invention is to provide a flooring systemthat has great flexibility so as to make various shapes, sizes, andbevel edges.

Another feature of the present invention is to provide a flooring systemthat can alleviate the requirement of installing the plank in a givenorientation.

Also, a feature of the present invention is to provide a surfacecovering system which has the ability to tolerate some imperfections inthe sub-floor or substrate and thus avoid telegraphing the imperfectionson the surface covering itself.

A further feature of the present invention is to provide a surfacecovering system which has improved damaged resistance properties, suchas improved impact strength and the like, especially in the joint areas.

Additional features and advantages of the present invention will be setforth in the description which follows, and in part will be apparentfrom the description, or may be learned by practice of the presentinvention. The features and other advantages of the present inventionwill be realized and attained by means of the elements and combinationsparticularly pointed out in the written description and appended claims.

To achieve these and other advantages and in accordance with thepurposes of the present invention, as embodied and broadly describedherein, the present invention relates to a spline, tongue, connector, orsnap connector for connecting two or more planks together. The spline ispreferably made from a polymeric material and has a shape and dimensionssuch that the spline has a sufficient width to fit into and extendoutside of a groove on a side edge of a first plank and also to fit intoa respective groove on a side edge of a second plank. The spline mayalso be shaped such that when the first plank and the second plank areconnected together by the spline, the spline is concealed from view.

The present invention further relates to a surface covering system forconnecting two or more planks together. The surface covering systeminvolves two or more planks and at least one spline. The planks eachhave a groove on at least one side edge and the spline is a polymericmaterial having a shape and dimensions such that the spline has asufficient width to fit into and extend outside of a groove on a sideedge of a first plank and to fit into a respective groove on a side edgeof a second plank. The spline may be concealed from view when the firstplank and the second plank are connected together by the spline or maybe wide enough to show when the first and second planks are connectedtogether.

The present invention further relates to a plurality of planks connectedtogether by one or more splines. Each plank has a groove on at least oneside edge thereof and the spline is a polymeric material having a shapeand dimensions such that the spline has a sufficient width to fit intoand extend outside of a groove located on the side edge of a first plankand to fit into a respective groove located on a side edge of a secondplank. The spline, as described above, may be concealed from view whenthe first plank and the second plank are connected together by one ormore splines.

Finally, the present invention also relates to a method to connect twoor more planks together and involves inserting one edge of a spline intoa groove in one plank and inserting the opposite edge of the spline intoa groove on a second plank. The spline is a polymeric material having ashape and dimensions such that the spline has a sufficient width to fitinto and extend outside a groove located on a side edge of a first plankand to fit into a respective groove located on a side edge of a secondplank. The spline may be concealed from view when the first plank andthe second plank are connected together by the spline, or may showthrough between the planks.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are intended to provide further explanation of the presentinvention, as claimed.

The accompanying drawings, which are incorporated in and constitute apart of this application, illustrate several embodiments of the presentinvention and together with the description serve to explain theprinciples of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing one embodiment of a spline of thepresent invention.

FIG. 2 is a schematic diagram showing a side view of a spline design ofthe present invention which can be used to connect planks together.

FIG. 3 is a schematic diagram of a sectional view showing anotherembodiment of a spline of the present invention.

FIG. 4 is a schematic diagram illustrating a groove design on a side ofa plank according to an embodiment of the present invention showing thegroove that locks with a spline of the present invention.

FIGS. 5 and 6 are schematic diagrams showing additional embodiments ofsplines of the present invention.

FIG. 7 is an end view of a plank having a spline in each of opposingedge grooves of the plank.

FIG. 8 is an end view of a substantially rectangular-shaped splineaccording to an embodiment of the present invention showing variousdimensions of the spline in inches (″).

FIG. 9 is an end view of a substantially rectangular-shaped splineaccording to another embodiment of the present invention showing variousdimensions of the spline in inches (″) and showing angled teeth on thetop (right-side) and bottom (left-side) surfaces of the spline.

FIG. 10 is an end view of a substantially rectangular-shaped splineaccording to another embodiment of the present invention showing variousdimensions of the spline in inches (″) and protruding beads that extendin the direction of elongation of the spline on both the top and bottomsurfaces of the spline.

FIG. 11 is an end view of a substantially rectangular-shaped splineaccording to another embodiment of the present invention showing variousdimensions of the spline in inches (″) and showing a recessed portion ofthe core which accommodates toothed-protrusions.

FIG. 12 is an end view of a substantially rectangular-shaped splineaccording to yet another embodiment of the present invention showingvarious dimensions of the spline in inches (″) and showing a protrudingbead on an otherwise flat top surface of the spline and a protrudingbead along with teeth on the bottom surface of the spline.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

In general, the present invention relates to a spline, tongue,connector, or snap connector for connecting two or more planks togetherto form a surface covering. Preferably, the surface covering is forflooring surfaces. The spline of the present invention and the surfacecovering system of the present invention can be used in a variety ofapplications including, but not limited to, wall panels, ceiling panels,decks, patios, furniture surfaces, shelving, and other surface coveringsor parts thereof.

The spline of the present invention can be used to connect a variety ofsurface covering products. Any surface covering product having theability to be formed or manufactured such that grooves can be created toreceive the spline of the present invention can be used as part of thisinvention to form surface coverings. For instance, laminate floorproducts can be connected by the spline of the present invention. Otherfloor products that can be connected together by the spline of thepresent invention include, but are not limited to: plastic-containingproducts such as hard surface products where the groove can be formed byextrusion molding, injection molding, and the like; and cellulosic-typeproducts wherein a groove can be machined into the part to receive thespline. Products of dissimilar materials can also be joined using thespline of the present invention.

Besides floor coverings, other surface covering products that can beconnected together by the spline of the present invention include, butare not limited to, ceiling tiles, wall paneling, deck paneling, fascia,partition panels, horizontal surfaces, table tops, chest tops, andcounter tops.

The surface covering products that are connected together by the splineof the present invention preferably have at least one side edge of thesurface covering product having a groove to receive the spline of thepresent invention. A second surface covering product should also have atleast one side that has a groove on the side edge to receive the otheredge of the spline in order to connect two or more surface coveringproducts together.

The spline of the present invention preferably is a polymeric material.The polymeric material that the spline is made from is preferably athermoplastic material although other types of polymers can be used.Examples of polymeric materials that can be used to form the splineinclude, but are not limited to, polyvinyl chloride, polyvinylchloride/rubber blends, acrylonitrilebutadiene styrene (ABS),polyethyleneterephthalate (PET), polybutyleneterephthalate (PBT), otherpolyesters, polyolefins, and the like. The spline can be formed by anytechnique, such as extrusion techniques. A die having the shape of thespline can be extruded through an extruder such as one from AmericanMaplan Corporation, e.g., Model TS-88, which has the ability to processrigid PVC profiles with a maximum output capacity of about 900pounds/hour, based on a compound bulk density of 37 lb/ft³. The TS-88 isa twin screw extruder which has a barrel heating section as well as avacuum section. In this preferred extruder, there are 12 temperaturezones with 6 for cooling and a temperature control system.

The spline of the present invention can also be formed by other moldingtechniques or other conventional technology used to form polymericmaterials having desired shapes and forms.

The spline is shaped such that it can connect two or more plankstogether. In particular, the spline has a shape and dimensions such thatthe spline has a sufficient width to fit into and extend outside of agroove on a side edge of a first plank and to fit into a respectivegroove on the side edge of a second plank. The spline may be shaped suchthat the spline is concealed from view when the first and second planksare connected together by the spline, or it may have a wider width suchthat the spline can be seen when the planks are connected. The spline ispreferably rectangular-shaped. The sides of the spline that fit into thegrooves of the plank are preferably flanged, toothed, flat, or include acombination of such designs. These types of design on the edges of thespline serve to provide a snug or tight fit within the grooves of theplanks, for example, the grooves exemplified in the drawings. Each plankpreferably has a groove in two or more side edges of the plank.

According to an exemplary system of the present invention, a system isprovided whereby the planks of the system have a flanged or toothedgroove on at least one side edge thereof. Preferably, the systemincludes a spline having a flat surface on at least one side edgethereof, and a plank with a groove having teeth that engage the flatsurface of the spline.

The spline can optionally have tooth-shaped notches on the top andbottom surfaces that engage the top and bottom surfaces of the groovesin the plank in order to also create a snug and tight fit. The splinecan have a combination of toothed, flanged, protruding, beaded, and/orflat portions on the top and/or bottom surfaces. The width of the splineand thickness of the spline are based on the depth and height of thegrooves in the planks for which the spline is used to connect two ormore planks together. Depending on the product that the spline isconnecting, the spline can be made to match the grooves for a snug andtight fit. For instance, the spline can have a thickness of from about0.1 inch to about 0.2 inch and a width of from about 0.4 inch to about0.6 inch in order to fit into a groove in the side of a plank having adepth of from about 0.2 inch to about 0.3 inch and a groove height offrom about 0.1 inch to about 0.2 inch. More specifically, the spline canhave a thickness of from about 0.153 inch to about 0.156 inch and awidth of from about 0.485 inch to about 0.490 inch in order to fit intoa groove in the side of a plank having a depth of from about 0.250 inchto about 0.280 inch and a groove height of from about 0.145 inch toabout 0.151 inch.

As stated above, the spline preferably has a sufficient width such thatthe spline is able to adequately connect two or more planks together byinserting the spline into a groove of one plank and then into a grooveof a second plank. When the two planks are connected together, thespline is preferably and entirely concealed from the visual surface ofthe surface covering. Tolerance considerations should be taken intoaccount such that preferably the maximum contact between the groove andthe top and bottom spline surfaces is maintained but preferably narrowenough to be less than the combined groove depth of adjacent planksgrooves to be joined together so that the top surfaces of the plankswill hide the spline. According to an alternative embodiment of thepresent invention, the combined depth of the adjacent planks is notsufficient to conceal the entire spline such that some of the spline canbe seen when the planks are connected together.

In a preferred embodiment, the spline is preferably a co-extrudedmaterial and more preferably is a co-extruded material made from a rigidthermoplastic material in the central portion of the spline and a softthermoplastic material at the top and bottom surfaces of the spline,wherein the softer material engages the grooves of two or more planks.The soft thermoplastic material is preferably polyvinyl chloride or ablend of polyvinyl chloride and nitrile rubber. This soft thermoplasticmaterial has the ability to be more flexible and thus create a tighterfit when engaging the grooves of the planks, and allows a highertolerance to fit. In the case of appropriately soft teeth, a splinethickness of from about 3 mil to about 38 mil greater than the grooveheight can be tolerated. A rigid central portion of the spline ispreferably provided and enables rigidity and strength needed in orderfor the spline to be handled and inserted into the grooves of theplanks.

The spline can be any length such as from about 4 feet to about 9 feet,for example, from about 55 inches to about 75 inches, and morepreferably from about 6 feet to about 8 feet long. Preferably, thelength of the spline exceeds the length of the planks to be joined. Forexample, a plurality of splines, each having a length of about 7 feet,is preferably used to join a plurality of planks, each having a lengthof about 6 feet.

In addition, while not necessary, the spline can further have anadhesive or bonding agent applied to the surfaces that engage thegrooves of the planks in order to create an even stronger connectionbetween the planks and splines. Such adhesives that can be used include,but are not limited to, solvent welds which fuse the spline/plankinterface by partially dissolving and swelling the spline and plank attheir interface, epoxies, urethanes, and other cross-linking adhesives.Preferably, the adhesive or adhesive system provides a water-imperviousbond, and preferable adhesives of this type include solvent welding orcrosslinkable adhesives.

For purposes of the present invention, the term “plank” is usedthroughout and includes, but is not limited to, flooring planks,laminate flooring planks, floor tiles, laminate floor tiles, deckpaneling, fascia, partition panels, horizontal surfaces, table tops,chest tops, and counter tops.

The remaining sides of the planks can also have grooves. For instance,the planks can have a groove on two or more sides of the edges of theplank, wherein the sides or edges are opposite to each other. The plankpreferably has grooves on at least one side edge thereof and preferablyon at least opposing sides. The remaining edges or sides of the plankcan also have grooves or they may include tongues or can have no groovesor tongues whatsoever.

Though not necessary, the ends of the plank as well as the tongue and/orgroove can have a bonding agent applied to these locations in order toseal or bond the planks together.

In the present invention, while each of the laminate planks can beaffixed to the sub-floor or substrate, the laminate planks using theconnecting system of the present invention can be attached only to eachother through the groove and splines such that a floating floor systemis provided. This promotes fast and easy laying of the floor system.

With the use of the connecting system of the present invention, thepresent invention achieves many benefits and advantages, such asmoisture resistance.

Also, in the preferred embodiment of the present invention, theinstallation method used as a result of the splines of the presentinvention, preferably eliminates the glue needed for tongue and grooveconnections.

A full-spread adhesive can be applied between the underside of theplanks and the sub-floor surface. This provides the advantages of addeddimensional stabilization and sound deadening. Both of these propertieswould be beneficial in commercial applications.

In addition, the excellent moisture resistance of this surface coveringsystem can eliminate the need for underpadding, though the use ofunderpadding is an option.

With reference to FIG. 1, FIG. 1 represents a schematic diagram of anend view of one embodiment of the plank with a spline. FIG. 1. is aperspective view looking at the front edge of the plank wherein thegroove 76 would run along each longitudinal edge 72 of the plank. Thespline 64 is inserted along the length of each groove 76. The plank edge72 has the groove 76. Also labeled are the plank bottom surface 68 andtop surface 70.

Referring to FIG. 2, FIG. 2 is a representation of a type of spline 64that can be used in an embodiment of the present invention. As can beseen in FIG. 2, a preferably soft material 82 such as flexible PVC islocated on the top and bottom surface of the spline in order to ensure atight fit with the groove of the plank. Preferably, the plank is athermoplastic plank. The spline design preferably has a thickness thatis from about 3 mils to about 5 mils thicker than the groove of theplank in this embodiment. Depending upon the design of the spline, theease of insertion into the groove can vary. For example, teeth or barbscan be formed on the top and/or bottom surfaces of the spline core.These teeth or barbs can be aimed is such a direction that insertion canbe very easy, yet the spline is very difficult to remove from the grooveof the plank. For example, the teeth can point in a directionsubstantially opposite to the direction of insertion of the spline intothe groove. An exemplary angle for the teeth is from about 95° to about170°, for example, about 135°, with respect to the direction ofinsertion. This relationship between the teeth and groove provides astrong plank-to-plank connection. If the spline is too thick, it canopen the groove and cause edge peaking, and can be difficult to install.If the spline is too thin, it does not effectively engage with the teethin the groove and can result in a weak connection. The edges of thespline or tongue 64 are tapered or beveled as shown at 80 in order toensure that the tongue can readily be inserted into the groove.

In the embodiment shown in FIG. 2, the overall width of the spline ortongue 64 (from left to right) is 0.500 inch and the overall height is0.155 inch. The thickness of the soft material 82 shown on the top andbottom of the spline or tongue is 0.023 inch. For example, over a sevenfoot length, for each of the top and bottom surfaces of the spline, therespective surface is made up of 0.064 square inch of a ridgedpolyvinylchloride (PVC) material and 0.019 square inch of a softpolyvinylchloride material. The angled corners of the spline or tongue64 are each angled about 30° with respect of the flat top and bottomrespective adjacent surface of the spline or tongue 64FIG. 3 makesreference to a spline 64 which has teeth 90 on its surfaces which engagethe grooves 76 of the planks. Further, as can be seen in FIG. 3, in apreferred embodiment, the top surfaces of the plank can form a V shapevalley 88 and the top edges of the adjacent planks touch each otherwhereas the bottom edge portions of each respective plank are cut inorder to have a slightly shorter length and thus form a gap 86 whichensures that the top ends 88 touch each other and do not leave any gapson the walking surface of the planks. Reference numeral 84 shows a planktop layer, such as a print layer, a composite print layer, or the like.

In the embodiment shown in FIG. 3, the width dimension of the gap 86(from left to right) is 0.030 inch. The thickness of the top layer 84shown in FIG. 3 is 0.015 inch. The two connected planks shown in FIG. 3,each have dimensions of about 7.0 inches in width and about 72 inches inlength, and each can be provided with 13 feet or strips 62. A protrudingbead 91 is provided along the midline of the top surface of the spline93 and rests between the adjacent side edges of the joined planks.

Referring to FIG. 4, FIG. 4 is a depiction of a groove 76 which hasreceiving teeth 92 for a spline or tongue of the design shown at 90 inFIG. 3. In the embodiment shown in FIG. 4, the foot 62 has a width of0.075 inch, a height of 0.075 inch, and is housed in a correspondinggroove or hole that extends 0.050 inch into the bottom surface of theflooring plank. The beveled or tapered edge 78 shown in FIG. 4 is angledin an amount of 17° relative to the flat top surface of the plank. Thebeveled or tapered bottom edge opposite edge 78 is angled in an amountof 30° relative to the flat bottom surface of the plank. The receivingteeth 92 are each 0.040 inch wide (from left to right) and each has aflat top surface at its point that has a width of 0.008 inch. The gapbetween opposing top and bottom teeth is 0.150 inch. The depth of thegroove 76, from the edge of the plank to the deepest part of groove 76(from left to right) is 0.270 inch and the depth from the left edge ofthe plank to and including the last tooth within the groove is 0.201inch. The beveled or tapered edge 78 intersects with the flat topsurface of the plank 0.125 inch from the edge of the plank.

FIGS. 5 and 6 represent various different widths of the plank butgenerally show the same features as shown in FIG. 1 and the referencenumerals in FIGS. 5 and 6 represent the same features as thecorresponding numerals represented in FIG. 1.

The embodiment shown in FIG. 5 are substantially identical to thedimensions shown in FIG. 1 with the exception that the overall width ofthe plank shown in FIG. 5 is 3.000 inches as opposed to 7.000 inches forthe width of the plank shown in FIG. 1. In addition, the two verticalside walls adjacent each respective gap 76, herein referred to as thetwo outermost side walls, are 0.075 inch in width as opposed to 0.116inch in width for the corresponding outermost side walls of theembodiment shown in FIG. 1. The overall height of the plank shown inFIG. 5, from the flat top surface to the flat bottom surface (excludingthe feet or strips 62 is 0.355 inch for the embodiment shown in FIG. 5,and from about 0.370 inch to about 0.375 inch including laminateadhesive.

For the embodiment shown in FIG. 6, the dimensions are substantiallyidentical to those dimensions shown in the embodiment of FIG. 5, withthe exception that the plank shown in FIG. 6 has an overall width of5.000 inches.

FIG. 7 shows yet another embodiment of a plank and spline system of thepresent invention. The plank includes U-shaped or Π-shaped recesses inthe bottom surface 94 thereof. The top surface 92 of the plank is flat.A pin 98 and a hole 100 are provided at each end of the plank foraligning the hole and pin of one plank with a respective pin and hole ofan adjacent plank.

FIG. 8 is an end view of a substantially rectangular-shaped splineaccording to an embodiment of the present invention showing variousdimensions of the spline in inches (″). A core 110 is at least partiallycovered with a softer, more flexible, more resilient and/or more elasticsurface material 112. The material useful for forming the core 110 canbe a resinous material such as hard homopolymeric polyvinylchloride(PVC) material. An exemplary homopolymeric PVC material for the corematerial is GEON 8700 or 8700 A available from BF Goodrich of Cleveland,Ohio, which has a density of 1.38 g/cc per ASTM D-792, and a hardnessdurometer of D=78 as per ASTM D-2240. An exemplary softer material forthe surface material is an extrudable vinyl elastomer, for example,NOROPLAZ 8602 available from North American Plastics, Inc. of Aberdeen.Miss., which has a density of 1.23 g/cc per ASTM D-792 and a hardnessdurometer of D=59 as per ASTM D-2240.

FIG. 9 is an end view of a substantially rectangular-shaped spline 122according to another embodiment of the present invention showing variousdimensions of the spline 122 in inches (″) and showing angled teeth onthe top (right-side) and bottom (left-side) surfaces (116, 118) of thespline. A core 120 is at least partially covered with a softer, moreflexible, more resilient and/or more elastic surface material 124. Thesurface material includes teeth 114 on both the top surface 116 and onthe bottom surface 118 of the spline 122. The material useful forforming the core 120 can be a resinous material such as hardhomopolymeric polyvinylchloride (PVC) material. An exemplaryhomopolymeric PVC material for the core material is GEON 8700 or 8700 A.An exemplary softer material for the surface material is an extrudablevinyl elastomer, for example, NOROPLAZ 8602.

FIG. 10 is an end view of a substantially rectangular-shaped spline 130according to another embodiment of the present invention showing variousdimensions of the spline 130 in inches (″) and raised relief elements orprotruding beads 132, 134 that extend in the direction of elongation ofthe spline 130 on the respective top surface 146 and bottom surface 148of the spline. A core 140 is at least partially covered with a softer,more flexible, more resilient and/or more elastic surface material 142.The surface material includes teeth 144 on both the top surface 146 andon the bottom surface 148 of the spline 130. The material useful forforming the core 140 can be a resinous material such as hardhomopolymeric polyvinylchloride (PVC) material. An exemplaryhomopolymeric PVC material for the core material is GEON 8700 or 8700 A.An exemplary softer material for the surface material 142 is anextrudable vinyl elastomer, for example, NOROPLAZ 8571 available fromNorth American Plastics, Inc. of Aberdeen. Miss., which has a density of1.23 g/cc per ASTM D-792 and a hardness durometer of D=59 as per ASTMD-2240.

FIG. 11 is an end view of a substantially rectangular-shaped spline 150according to another embodiment of the present invention showing variousdimensions of the spline 150 in inches (″) and showing a recessedportion 161 of the core 160 that accommodates toothed-protrusions. Thespline is provided with angled teeth on the top surface 154 (right-side)and bottom surface 156 (left-side) of the spline. A core 160 is at leastpartially covered with a softer, more flexible, more resilient and/ormore elastic surface material 162. The material useful for forming thecore 160 can be a resinous material such as hard homopolymericpolyvinylchloride (PVC) material. An exemplary homopolymeric PVCmaterial for the core material is GEON 8700 or 8700 A. An exemplarysofter material for the surface material 162 is an extrudable vinylelastomer, for example, NOROPLAZ 8602.

FIG. 12 is an end view of a substantially rectangular-shaped spline 170according to yet another embodiment of the present invention showingvarious dimensions of the spline 170 in inches (″) and showing aprotruding bead 172 on an otherwise flat top surface 174 of the spline170. Also shown are a protruding bead 176 along with teeth 178 on thebottom surface 180 of the spline 170. The protruding beads run along themidlines of the respective top and bottom surfaces. The material usefulfor forming the core 190 can be a resinous material such as hardhomopolymeric polyvinylchloride (PVC) material. An exemplaryhomopolymeric PVC material for the core material is GEON 8700 or 8700 A.An exemplary softer material for the surface material 182 is anextrudable vinyl elastomer, for example, NOROPLAZ 8571.

The surface covering system of the present invention can be used in avariety of applications including, but not limited to, wall panels,ceiling panels, flooring surfaces, decks, patios, furniture surfaces,shelving, deck paneling, fascia, partition panels, horizontal surfaces,table tops, chest tops, and counter tops, and other surface coverings orparts thereof.

Other embodiments of the present invention will be apparent to thoseskilled in the art from consideration of the specification and practiceof the present invention disclosed herein. It is intended that thespecification and examples be considered as exemplary only, with thetrue scope and spirit of the present invention being indicated by thefollowing claims.

What is claimed is:
 1. A spline for connecting two or more surfacecovering planks together, said spline comprising a polymeric materialhaving an elongated shape and a width and height that are perpendicularto a direction of elongation of the spline, wherein said width issufficient to fit into and extend outside of a groove in a side edge ofa first plank and fit into a respective groove in a side edge of asecond plank, and wherein said spline includes a top surface and abottom surface, each having a soft thermoplastic material, and edgesurfaces having a hard thermoplastic material.
 2. The spline of claim 1,wherein said spline is concealed from view when said first plank andsaid second plank are connected together by said spline.
 3. The splineof claim 1, wherein said spline is rectangular-shaped.
 4. The spline ofclaim 1, wherein said spline is rectangular-shaped and each side edgethat fits into a groove of a plank is beveled.
 5. The spline of claim 1,wherein said spline has tooth-shaped notches on both said top and bottomsurfaces, wherein said notches are adapted to the fit into grooves ofthe first plank and the adjacent second plank.
 6. The spline of claim 1,wherein said spline has tooth-shaped notches on one of said top andbottom surfaces, wherein the other of said top and bottom surfaces isflat.
 7. The spline of claim 1, wherein said spline has a top surface, abottom surface, and tooth-shaped notches on one of said top and bottomsurfaces and wherein the other of said top and bottom surfaces is flatexcept for the presence of a raised relief element along a midline ofthe flat surface, said midline elongated in the direction of elongationof said spline.
 8. The spline of claim 1, wherein said spline comprisesan extruded polymeric material.
 9. The spline of claim 1, wherein saidspline comprises an extruded thermoplastic material.
 10. The spline ofclaim 1, wherein said spline comprises a co-extruded material.
 11. Thespline of claim 1, wherein said spline comprises a co-extruded materialmade from rigid thermoplastic material in a central portion of thespline and a soft thermoplastic material at the top and bottom surfacesof the spline.
 12. (The spline of claim 1, further comprising aprotruding bead along a midline of said top surface of said spline. 13.The spline of claim 1, wherein edges of said spline are tapered orbeveled.
 14. A surface covering system for connecting two or morethermoplastic planks together, said system comprising two or morethermoplastic planks including a first plank and a second plank, and atleast one spline that is elongated in a direction of elongation, whereineach plank has a groove on at least one side thereof, and said splinecomprises a polymeric material having a shape such that said spline hasa sufficient width to fit into and extend outside of a groove in theside edge of the first plank and to fit into a respective groove in aside edge of the second plank, wherein said spline includes a topsurface and a bottom surface, each having a soft thermoplastic material,and edge surfaces having a hard thermoplastic material.
 15. The surfacecovering system of claim 14, wherein said spline is concealed from viewwhen said first plank and said second plank are connected together bysaid spline.
 16. The surface covering system of claim 14, wherein saidsurface covering is a floor or floor covering.
 17. The surface coveringsystem of claim 14, wherein said surface covering is a laminate floor.18. The surface covering system of claim 14, wherein said at least onespline has tooth-shaped notches on both said top and bottom surfaces,wherein said notches fit into the respective grooves of the first plankand the second plank.
 19. The surface covering system of claim 14,wherein said at least one spline has tooth-shaped notches on one of saidtop and bottom surfaces, wherein the other of said top and bottomsurfaces is flat.
 20. The surface covering system of claim 14, whereinsaid at least one spline has tooth-shaped notches on one of said top andbottom surfaces, and wherein the other of said top and bottom surfacesis flat except for the presence of a raised relief element along amidline of the flat surface, wherein the midline extends along thespline in the direction of elongation of the spline.
 21. The surfacecovering system of claim 14, wherein each said groove in the at leastone side of each of the first and second planks has teeth that engage atleast one of said top and bottom surfaces of said spline.
 22. Thesurface covering system of claim 21, wherein said spline has at leastone flat surface that engages the teeth in each of said grooves.
 23. Aplurality of thermoplastic planks connected together by one or moresplines, wherein each plank has a groove on at least one side thereof,wherein said groove includes at least one receiving tooth; wherein saidspline includes a top surface and a bottom surface, each having a softthermoplastic material, and edge surfaces having a hard thermoplasticmaterial, and wherein each said spline is elongated in a direction ofelongation and comprises a polymeric material having a shape such thatsaid spline has a sufficient width to fit into and extend outside of agroove in a side edge of a first plank and to fit into a respectivegroove in a side edge of a second plank, and wherein said first plank,second plank, splines, grooves, or any combinations thereof includes abonding agent.
 24. The plurality of thermoplastic planks of claim 23,wherein said one or more splines is concealed from view when theplurality of planks are connected together with said one or moresplines.
 25. The plurality of thermoplastic planks of claim 23, whereinsaid one or more splines each has a top surface, a bottom surface, andtooth-shaped notches on both said top and bottom surfaces, wherein saidnotches fit into the grooves of the plurality of planks.
 26. Theplurality of thermoplastic planks of claim 23, wherein each said groovein the at least one side edge of each of the first and second planks hasteeth that engage at least one of said top and bottom surfaces of saidone or more splines.
 27. A method to connect two or more thermoplasticplanks together comprising inserting one edge of an elongated splineinto a groove in a side edge of one plank and inserting the oppositeedge of the spline into a groove in a side edge of a second plank, saidspline comprising a polymeric material having a shape and dimensionssuch that said spline has a sufficient width to fit into and extendoutside of the groove in the side edge of the first plank and to fitinto the groove in the side edge of the second plank, and wherein saidgroove of said first plank and said groove of said second plank includeat least one receiving tooth, and wherein said spline includes a topsurface and a bottom surface having a soft thermoplastic material andedge surfaces having a hard thermoplastic material, and wherein saidfirst plank, second plank, groove, spline, or any combinations thereofincludes a bonding agent.
 28. The method of claim 27, wherein saidspline is concealed from view when said first plank and said secondplank are connected together with said spline.
 29. The method of claim28, wherein said spline has tooth-shaped notches on both said top andbottom surfaces, wherein said notches fit into the grooves of the firstplank and the second plank.
 30. The method of claim 28, wherein said atleast one tooth engages at least one of said top and bottom surfaces ofsaid spline.